Batman/Superman or Justice League movie?

With the casting of Wonder Woman for the Batman/Superman movie,I’m starting to wonder what WB/DC is thinking?
The actress casted as Wonder Woman isn’t what I’m worried about.
I’m worried about the script they’re using for the film.

And Wonder Woman may not be the only superhero in the film.
With rumors of Flash,Nightwing,and Martian Manhunter making cameos,I’m starting to think WB/DC is making a JLA movie.

I know they’re trying to play catch up with Marvel/Disney,but I’m worried that they may go too far with this film.
Yes,I and every fanboy & girl wants a JLA movie,but I think they’re rushing it to beat Marvel/Disney.
Plus,there isn’t enough screen time for each hero to have any character development if they go this route.